1. Field of the Invention
The present invention relates to an apparatus for inspecting loss of optical transmission of optical fibers which are arrayed in one row or in plural rows and which constitute an optical fiber assembly.
2. Description of the Prior Art
Extreme difficulties have hitherto been encountered in measuring optical transmission loss of an optical fiber assembly composed of optical fibers arrayed in one row or in plural rows without collapsing the form of fiber arrangement. The reason for this is due, for example, to the fact that there are no means with efficiency and yet with high precision for irradiating a measuring light beam onto only a specific optical fiber without stray light. A method of taking apart each end of the optical fiber assembly into individual optical fibers and mesuring irregularities in optical transmission loss thereof has therefore been used. In this method, however, when the number of optical fibers constituting the optical fiber assembly is increased, a large amount of time is needed to take it apart into individual fibers. In addition, in case of a step index optical fiber assembly, there is a possibility that the interface between the core and cladding is broken down when the assembly is taken apart.
When measuring the optical transmission loss, the end face of each optical fiber is polished to a uniform surface roughness of for the purpose of making the measurement variation small. It is very difficult, however, to polish such end face uniformly for each fiber.
Thus, in the optical fiber assembly having a large number of optical fibers, much time is conventionally required for taking it apart into individual fibers, polishing, and measuring as mentioned above.